1. Field of the Invention
The present invention relates to a decorative laminated sheet having a colored layer or a pattern-printed layer, having transparency, a quality feel and a coated appearance, and a process for producing same. In particular, the present invention relates to a decorative laminated sheet having a sense of being coated, which is produced by laminating a polyester film having an excellent transparency on the surface of a semi-rigid thermoplastic resin film on which a colored layer or a pattern-printed layer is applied, and then coating the surface of the resulting laminated film with a hard coat layer comprising an ultraviolet-curable coating to improve the surface hardness, as well as to a process for producing same.
2. Description of the Prior Art
There have been known methods for producing decorative plywood for cabinets, such as a method in which a thermoplastic resin having a colored layer or a pattern-printed layer, e.g., a polyvinyl chloride (PVC) sheet, is laminated on the surface of a woody base material, e.g., a middle-density fiber board (MDF); and a method in which a composite sheet, which is prepared by dry-laminating a polyester (PET) film having excellent transparency on the surface of a thermoplastic resin having a colored layer or a pattern-printed layer such as a PVC sheet, is laminated on the surface of a woody base material such as an MDF.
In such cases, however, the lamination of only a PVC sheet exhibits poor hardness. On the other hand, although PET film per se has sufficient hardness, it tends to be easily scratched by abrasion. Therefore, such laminating treatments are practically disadvantageous.
In addition, there have also been known other methods for producing decorative plywood, in which a sheet that has improved surface hardness from coating an ultraviolet (UV)-curable coating on the surface of a thermoplastic resin having a colored layer or a pattern-printed layer, e.g., a PVC sheet, is laminated on the surface of a metallic or woody base material (Japanese patent Application Nos. 75229/1989 and 176141/1991).
In such methods, however, the UV-curable coating is too rigid. Therefore, the phenomenon that, when the plywood produced by laminating the coating film and the PVC sheet successively on a woody base plate such as an MDF, is subjected to so-called V-cut processing and then bent, the surface coating film of the plywood can not stretch and cracks, and furthermore, the PVC sheet is destroyed.
As mentioned above, the conventional surface-covering sheets are insufficient in scratch resistance, sharpness and specular reflectivity, and are poor in having a coated appearance as decorative laminated sheets owing to transparency and in having a feeling of depth. Therefore, improved surface covering sheets have been desired for such decorative laminated sheets.
On the other hand, there has been cabinet decorative plywood obtained by laminating a thermoplastic resin having a colored layer or a pattern-printed layer, e.g., a PVC sheet, on the surface of a woody base material, e.g., an MDF, followed by post-coating the surface of the PVC sheet to give transparency and an appearance of depth and to endow it with scratch resistance.
However, such decorative plywood has various defects such as a complicated post-coating process, cost and environmental pollution caused by use of organic solvents.
The object of the present invention is to solve the above-mentioned problems in conventional decorative laminated sheets, and to provide a sheet for cabinet decorative plywood which has transparency and an appearance of depth and which also has excellent scratch resistance, and further to provide a decorative laminated sheet having a coated appearance and improved V-cut processability.